DSP-10 from W7PUA: Hints for Assembly and Test

1. If you are using the Epson 10 MHz crystal for Y101, rather than the ICM crystal listed in QST, you will need to add capacitors across C108 and C108 as described on Parts Page.
2. The ground connection to the EZ-KIT Lite board is not shown explicitly. The negative lead for the power will probably handle the grounding, but two short ground wires from P3-1 and P3-50 to the box will make sure there is a good ground for the digital wires. No problem has been reported for the grounding of the analog lines. The 10 to 20 kHz range is reasonably immune from such problems. If there is any question, you can catch an analog ground in the area around J1 and J2 on the EZ-KIT board.
3. On the subject of P3. The pin numbering for P3 on the EZ-KIT board is confusing. This seems to relate to the PCB layout program that was used. Any reference to P3:2-xx should be P3-xx. The ':2' and ':1' are not needed.
4. Be careful in winding the toroids. Too tight and they will crumble into pieces. The best procedure is to just bring the turns snug. After the toroid is finished it can be helpful to cover it with "Polystyrene Q-Dope" (GC Electronics 10-3702).
5. By keeping the voltage going to the EZ-KIT to 9 Volts, the temperature of the U6 regulator on the EZ-KIT is hot, but not excessive, as long as the overall box is at room temperature. To provide some margin, one can attach a piece of metal between the regulator and the box. If this is bent at right angles it can be fastened with machine screws.